The effects of increasing concentrations of NaCl and CaCl2 on quince (Cydonia oblonga Mill. BA 29 clone) somatic embryogenesis and adventitious root regeneration were investigated. Leaves collected from in vitro-grown shoots were used as explants and induced for 2 d in liquid Murashige and Skoog medium containing 11.3 mM 2,4-dichlorophenoxyacetic acid. Explants were then cultured on semisolid Murashige and Skoog medium enriched with 4.7 mM kinetin and 0.5mM naphthaleneacetic acid under red light for 25 d and under white light for another 25 d. Two experiments were performed: in the first, NaCl was used at 0, 25, 50, 100, and 200mM in factorial combination with CaCl2 at 3, 9, and 27mM; in the second, NaCl was applied at 0, 5, 10, 20, 40, and 80mM in combination with CaCl2 at 0.3, 1.0, and 3.0mM. Quince leaves revealed the capacity to regenerate somatic embryos and/or adventitious roots. Quantitative and qualitative regeneration from leaves was affected by NaCl treatments: increasing NaCl concentrations, in combination with CaCl2 at 1mM, led to an increase in the proportion of leaves producing somatic embryos only, and to a decrease of both leaves regenerating roots only and leaves simultaneously producing somatic embryos and adventitious roots. This suggests a beneficial effect of salt stress on the embryogenic process. The regeneration response decreased with increasing salt concentrations and was almost totally inhibited above 50mM NaCl and 9mM CaCl2. The presence of CaCl2 in the culture medium apparently mitigated the effects of salt stress, but only when NaCl was applied at 40mM. NaCl at 5mM, in the presence of 0.3 or 1mM CaCl2, was favorable both to somatic embryo and root production. No value of the ratio Na+/Ca2+ was found to be optimal for the regeneration processes.
Increasing NaCl and CaCl2 concentration in the growth medium of quince leaves: I. Effects on somatic embryo and root regeneration
D'ONOFRIO, CLAUDIO;MORINI, STEFANO
2002-01-01
Abstract
The effects of increasing concentrations of NaCl and CaCl2 on quince (Cydonia oblonga Mill. BA 29 clone) somatic embryogenesis and adventitious root regeneration were investigated. Leaves collected from in vitro-grown shoots were used as explants and induced for 2 d in liquid Murashige and Skoog medium containing 11.3 mM 2,4-dichlorophenoxyacetic acid. Explants were then cultured on semisolid Murashige and Skoog medium enriched with 4.7 mM kinetin and 0.5mM naphthaleneacetic acid under red light for 25 d and under white light for another 25 d. Two experiments were performed: in the first, NaCl was used at 0, 25, 50, 100, and 200mM in factorial combination with CaCl2 at 3, 9, and 27mM; in the second, NaCl was applied at 0, 5, 10, 20, 40, and 80mM in combination with CaCl2 at 0.3, 1.0, and 3.0mM. Quince leaves revealed the capacity to regenerate somatic embryos and/or adventitious roots. Quantitative and qualitative regeneration from leaves was affected by NaCl treatments: increasing NaCl concentrations, in combination with CaCl2 at 1mM, led to an increase in the proportion of leaves producing somatic embryos only, and to a decrease of both leaves regenerating roots only and leaves simultaneously producing somatic embryos and adventitious roots. This suggests a beneficial effect of salt stress on the embryogenic process. The regeneration response decreased with increasing salt concentrations and was almost totally inhibited above 50mM NaCl and 9mM CaCl2. The presence of CaCl2 in the culture medium apparently mitigated the effects of salt stress, but only when NaCl was applied at 40mM. NaCl at 5mM, in the presence of 0.3 or 1mM CaCl2, was favorable both to somatic embryo and root production. No value of the ratio Na+/Ca2+ was found to be optimal for the regeneration processes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
